Drift compensating means for a quilting machine

ABSTRACT

In a quilting machine - of the type wherein a frame-mounted follower drives a carriage-mounted guide-track to move a carriage-mounted quilt assembly along a given path reproducing a given sewing line design while frame-mounted sewing means sews that design into the quilt - a drift correcting means is provided for shifting the track-supporting carriage relative to the track in the direction necessary, and in an amount sufficient, to correct or compensate for the pull-induced drift of the quilt assembly (relative to the carriage on which it is mounted) and thereby make the beginning and end points of the line of sewing coincide.

United States Patent Cash 1 May 30, 1972 s4 DRIFT COMPENSATING MEANS FOR A 3,263,633 8/1966 Hinko ..112/11s QUILTING MACHINE I Primary Examiner-James R. Boler [72] Inventor: David R. Cash, Loulsville, Ky. Assistant v Larkin 73 Assignee: James Cash Machine C0., Louisville, Ky. Mama-Arthur Rben [22] Filed: Dec. 29, 1970 [57] ABSTRACT [21] Appl- NO-i 1 2,4 In a quilting machine of the type wherein a frame-mounted follower drives a carriage-mounted guide-track to move a car- [52] U S Cl 2/118 riage-mounted quilt assembly along a given path reproducing 51] 35/00 a given sewing line design while frame-mounted sewing means Fieid 2/1134 19 79 R sews that design into the quilt a drift correcting means is 1 5/79 provided for shifting the track-supporting carriage relative to the track in the direction necessary, and in an amount sufficient, to correct or compensate for the pul|-induced drift of [56] References Clted the quilt assembly [relative to the carriage on which it is UNITED STATES PATENTS mounted] and thereby make the beginning and end points of the line of sewing coincide. 3,348,507 lO/l967 Kuhn ..ll2/l18 3 ,426,7 1 O 2/1969 Cash ..1 12/1 l8 12 Claims, 6 Drawing Figures Patented May 39, 1972 2 Sheets-Sheet 1 INVENTOR. DAVID R. CASH ATTORNEY Patented May 30, 1972 3,665,874

2 Sheets-Sheet 2 I5 r H a FRONT END INVENTOR.

DAVID R. CASH ATTORNEY DRIFT COMPENSATING MEANS FOR A QUILTING MACHINE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quilting machine of the type intended to sew a given endless sewing design into a quilt assembly.

2. Description of the Prior Art My prior US. Pat. Nos. 3,127,858, 3,180,293, 3,312,184, 3,421,464, 3,442,234 and 3,426,710 exemplify quilting machines of the above-identified type wherein a framemounted follower drives a carriage-mounted guide-track to move carriage-mounted quilt assembly along a fixed path reproducing a given endless sewing line design while framemounted sewing means sews that design into the quilt. So far as l know, none of the relevant prior art recognizes the fact that the sewing operation exerts, on the quilt assembly, a horizontal pull causing the quilt assembly to shift rearwardly relative to its holder and to the carriage on which it and its holder is mounted and that the net effect of that pull-induced shift is to space the end point of the sewing line a slight distance rearwardly, say 1 inch more or less, from the beginning point thereof and thereby prevent the beginning and end points from coinciding. Also, as far as I know, the prior art does not disclose any means for causing the beginning and end points to coincide by counteracting drift or compensating for it.

SUMMARY OF THE INVENTION Object of the Invention The principal object of the present invention is to provide a simple means for correcting or counteracting drift, and thereby making the beginning and end points of an endless sewing line design coincide.

Statement of the Invention The principal object of my invention is accomplished by providing means for shifting the track-supporting carriage forwardly relative to the track in an amount sufficient to cause the end point of the endless sewing line design to coincide with the beginning point thereof. I have found that, in a given quilting machine arranged to reproduce a given track design, if the machine will operate during one sewing cycle to space the end point of the sewing line design, say an inch rearwardly from the beginning point thereof, it may be expected consistently to reproduce that same spacing or drift. Accordingly, I provide means for shifting the track-supporting carriage one inch forwardly relative to the guide-track and thereby bring the end point of the sewing design into substantial coincidence with the beginning point thereof. At the end of each sewing cycle, the carriage is returned back to its original position in order to prepare it for the next sewing cycle.

Obviously, the shift could be progressively accomplished. However, I have found that the requisite shift may be efi'ected as a whole during a momentary fraction of the sewing cycle time and that it may be timed to occur at any time during the sewing cycle. As a matter of fact, I have obtained good results by effecting the shift very shortly after the beginning of the sewing cycle.

BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment of my invention is illustrated in the accompanying drawings wherein:

FIG. 1 is a perspective view of a front end portion of a tiltable head quilting machine provided with my invention, this view showing the head tilted and the carriage in its starting unshifted position;

FIG. 2 is a perspective view of a smaller front end portion of the same quilting machine, this view being taken from the lower left-hand side of FIG. 1;

FIG. 3 is a fragmentary perspective view of a fragmentary rear end portion of the machine, this view showing the relationship between the carriage-mounted rear stop and the guide plate;

FIG. 4 is a schematic view showing the relationship before shifting between the guide-track, the unshifted track-supporting carriage, the carriage-shifting unit comprising the operating cylinder which slides the carriage relative to the guidetrack, and the reversing valve controlling its operation, these parts being shown as they appear with the head fully tilted as in FIG. 1;

FIG. 5 is a schematic view showing the relationship (after shifting) between the guide-track, the shifted track supporting carriage and the operating cylinder-which shifted it; and

FIG. 6 is a schematic view of a conventional sewing line, this view indicating the spacing between the beginning and the end points.

CONVENTIONAL STRUCTURE The quilting machine shown in FIG. 1 on floor 1 conventionally comprises: (A) a metal frame composed of transversely spaced floor-supported upright side standards 2, a cross base frame 3 and a tiltable cross head-frame 4, both cross frames extending from one side standard 2 to the other side standard, which is not shown; (B) a frame-mounted sewing machine including a sewing head 5 mounted on the tiltable head-frame 4 and a cooperating thread-locking mechanism (not shown) mounted on the cross base frame 3; (C) movable carriage means including longitudinally extending transversely spaced floor-supported tracks 6, a thin lower carriage 7 mounted on tracks 6 for longitudinal back-and-forth movement along tracks 6 and an upper skeletonized box-like carriage 8 mounted on lower carriage 7 for transverse" side-toside movement at right angles to tracks 6; (D) a carriagemounted quilt 10 positioned over and mounted on the top-side of box-like carriage 8; (E) a frame-mounted follower 12; (F) a carriage-mounted guide-track unit composed of an endless sewing design guide-track 14 which is rigidly mounted on supporting plate 15 (located over and carried on the bottom side of the upper carriage 8) and which is engaged by a drive gear wheel (not shown) on follower 12; (G) motorized drive means (including a drive motor 18 mounted within a side standard 2) operative, when energized, to drive the sewing head and contemporaneously drive the track to move the carriage means from a given starting point along a path reproducing the pattern of said endless sewing line design. while the sewing mechanism sews that design into a carriage-mounted quilt; (H) start means to energize the motorized drive means at the beginning of each sewing operation, the start means including a start button 19 mounted on one of the side standards 2; and (I) means operative automatically, at the end of each sewing operation, to stop the sewing operation, retract the sewing needle, and tilt the tiltable cross frame 4 in a direction moving the sewing head 5 upwardly away from the quilt 10, said automatically operative means including a stop member 20 mounted on the carriage means in position to intercept and operate a frame-mounted stop switch (not shown) at the end of each sewing operation.

The foregoing quilting machine is described in greater detail in my US. Pat. No. 3,442,234 granted May 6, 1969, which is incorporated herein by reference only. In that patent, one feature involves having the sewing machine operate continuously from the beginning or starting point of one sewing cycle completely through that cycle plus a small fraction of the next cycle and then having the carriage move reversely to the cycle starting point. The description in the present case is not concerned with that particular feature.

In conventional operation, the start button 19 is operated to institute the sewing cycle by energizing the motor 18 and thereby operating both the frame-mounted follower l2 and the frame-mounted sewing machine. The follower drives the carriage-mounted sewing design guide-track 14 in a manner such as to move carriage-mounted quilt 10 along a path reproducing the endless sewing line design of guide-track 14. The contemporaneously energized sewing machine operates to sew the endless sewing line design into the quilt. At the end of the first sewing cycle, the stop member 20, on the carriage means, engages a stop switch (not shown) on the base frame 3, to shut the machine down whereupon the sewing needle is retracted and the head-frame tilted.

During the sewing operation, the quilt is subjected to a horizontal pull which may vary in direction from time to time but which stretches and shifts the quilt relative to the carriage in a manner causing the end point of the sewn design to be offset in one direction from its starting point. Thus, in FIG. 6, a conventional operation begins at starting point 25 and ends at the offset end point 26. I have found that, for each given run of quilts, the direction and magnitude of this offset or shift appears to be the same or substantially the same.

INVENTIVE STRUCTURE In accordance with my invention, the end point of the sewn design is made to coincide with the starting point 25 thereof by providing the quilting machine with an improvement comprising: (A) shift means interconnecting the guide-track and carriage, said shift means being actuatable in opposite ways of directions and being operative I) when actuated one way, to shift the carriage relative to the track in the contra offset (or offset correcting) direction from a normal position to a shifted position, and (2) when actuated the opposite way, to return the carriage relative to the track from its shifted position back to said normal position; (B) control means for actuating the shift means, said control means being operative, (1) during the sewing operation, to actuate the shift means in said one way to shift the carriage, and (2) following the end of the sewing operation, to actuate the shift means in said opposite way to return the carriage; and (C) stop means to restrict the magnitude of the shift and return movements of the carriage relative to the guide-track.

SHIFT MEANS While a variety of means may be employed to shift and return the carriage, my preferred arrangement employs a double acting air cylinder 28 having a piston 29 and a piston rod 30. The cylinder 28 is positioned over the front end of the bottom side of the "upper box-like carriage 8 and rigidly mounted thereon with its piston rod 30 projecting rearwardly toward the adjacent end of the guide-track supporting plate to which it is firmly connected at 31. This connection fixes the position of the piston 29 relative to the guide-track 14 and its supporting plate 15; hence, when air under pressure is fed to the right end of the air cylinder 28 of FIG. 4 to actuate that cylinder one way, that same right end of the cylinder will move to the right of FIG. 4 and, in doing so, yieldably force the upper box-like carriage 8 to move in the same rightward direction. In so doing, the bottom side of carriage 8 slides underneath plate 15 and, of course, relative to it. Similarly, when air under pressure is introduced into the opposite end of the air cylinder, that opposite end will move toward the plate 15 and yieldably force the carriage to move with it.

CONTROL MEANS While various control mechanisms may be employed to actuate the shift means, the control means comprises: a double acting control valve operative, when actuated one way, to actuate the shift means said one way to shift the carriage, and, when actuated the other way, to actuate the shift means said other way to return the carriage; and first and second valve actuating means operatively mounted on the carriage for movement therewith, the first means being arranged in position to designated by it as Model Z of its Duramatic" series of directional control valves. The valve 34 may be best disclosed by describing the mode of operation, which brought it to the position shown in FIG. 4, as follows: air under pressure from source 35 flows into a large air chamber 36, which houses shuttle valve 37, thence through conduit 38 into the left air chamber of the operating cylinder 28 forcing that cylinder to move left ward to the position shown in FIG. 4 while, at the same time, air is exhausted from the right air chamber of cylinder 28 through conduit 39 into the small air chamber 40 of the shuttle valve 37 from which the air is exhausted to atmosphere through conduit 41. The leftward movement of the cylinder returns the carriage to its nonnal starting position.

Each of the conduits 38 and 39 contains an adjustable metering mechanism which always pennits a full unrestricted flow of air into cylinder 28 but which is capable of metering any reverse flow of air to any value ranging from unrestricted to highly restricted. So long as shuttle valve 37 remains in its FIG. 4 position, the operating cylinder 28 will remain in its FIG. 4 position. However, when shuttle valve 37 is moved leftward (i.e. rearward) to the position wherein it connects conduit 38 to exhaust conduit 41, then the large air valve chamber 36 will be connected to conduit 39. Now air will flow from source 35 through chamber 36 and conduit 39 into the right air chamber of cylinder 28 to actuate that cylinder so that it moves rightward (i.e. forward) to the position shown in FIG. 5 wherein it has shifted the carriage to its offset position.

To move the shuttle valve 37 forwardly and rearwardly in the manner above described, the valve 34 contains a shuttle cylinder 43 having a shuttle piston 44 which is vertically bored at its lower side to receive the stem 45 of valve 37 and a spring 46 for pressing that stem and its valve member 37 downwardly. Here, it should beobserved that air under pressure from source 35 is always present in chamber 36 and that this chamber constantly leaks air around the upper side of shuttle valve 37 and upwardly along its stem 45 into a small passageway 47 passing axially through the center of shuttle piston 44 to communicate with both of its chambers; hence, both the left and right air chambers of shuttle cylinder 43 will normally be under full air pressure when the operating conditions are static. Movement of the shuttle valve 37 is obtained by reducing one or the other of the shuttle cylinders balancing pressures.

The actuating meansfor control valve 34 functions, at one time, to reduce the pressure in the left air chamber of the shuttle cylinder 43 and thereby cause the shuttle piston 44 to move valve 37 rearwardly and, at another time, to reduce the air pressure in the right air chamber of the shuttle cylinder and thereby cause the shuttle piston v44 to move valve 37 for wardly. Each of the two actuating means for the control valve 34 includes a pair of cooperative elements, one mounted on the carriage for movement therewith and the other mounted on the frame in position to operate the one element at a desired time.

The first cooperative element of one pair is in the form of an air bleeder 50 having a normally closed bleed valve 51 at its upper end and a conduit 52 connecting it to the left air chamber of shuttle cylinder 43. The air bleeder 50 is fixedly mounted on carriage 8 in a position such that its bleed valve 51 will be opened by thev second cooperative element at a desired time during the sewing operation. The second element may be the stationary frame of the quilting machine or some other member fixedly mounted on the frame. Preferably it comprises a frame-mounted bar 53 arranged to open the bleed valve 51 when the carriage 8 is to be shifted. When bleed valve 51 is opened, air flows from the left air chamber of shuttle cylinder 43 through conduit 52 and bleed valve 51 to at-v mosphere. This reduces the pressure at the left end of shuttle cylinder 43 rendering the air pressure at the right end thereof effective to move the shuttle piston 44 leftward. This moves the shuttle valve 37 leftward, causing valve 34 to connect source 35 to the right air chamber of operating cylinder 28 and thereby shift that cylinder from its FIG. 4 position to its FIG. 5 position.

The second valve actuating means similarly includes a pair of third and fourth cooperative elements. The third element, which is mounted on the carriage for movement therewith, comprises: an air bleeder designated 55; a bleed valve 56; and a conduit 57 connecting it to the right air chamber of shuttle cylinder 43. While the fourth element may be the tiltable head-frame 4 itself, it preferably comprises a bar 58 mounted on the tiltable head-frame in position to open the bleed valve 56 when the carriage 8 is to be returned.

STOP MEANS The carriage carries a pair of adjustable stop screws 60 and 61, one at each end. The front screw 60 determines the FIG. 4 position of the supporting plate on carriage 8; hence, this stop is adjusted to engage the plate 15 when the machine is ready to start the sewing operation. The stop 61 at the rear end of the machine is adjusted to set the FIG. 5 shifted position by engaging the plate 15 when the carriage 8 reaches its FIG. 5 position. The stroke of the operating cylinder is, of course, larger than the distance over which the carriage can be shifted and returned. This means that the cylinder 28, which yieldably urges the carriage in the shift and return directions, will be stopped before the cylinder 28 travels a full stroke in either the shifting direction or the return direction.

OPERATION While the operation should be clear from the foregoing, it may be helpful to summarize it, starting with the machine positioned to institute the sewing operation at point except that the head is tilted as indicated in FIG. 4. The first step, of course, is to untilt the head and thereby bring the sewing machine into operative relationship with a carriage-mounted quilt 10. The start button 19 is now pressed to energize the drive motor 18 and thus begin the sewing operation along line 64 as seen in FIG. 6.

The first pair of cooperative actuating elements for the control valve 34 may be located most anywhere along sewing line 64 but, as will be obvious, it should be very substantially in advance of the end point of that line. Preferably, the first pair is located at point 65 which is within, say, 1 to 4 inches from starting point 25. Between points 25 and 65, the carriage 8 may be presumed to follow line 64 also.

At point 65, the frame-mounted bar 53 opens the bleed valve 51 causing the shuttle cylinder 44 and shuttle valve 37 to shift to the right and thereby shift cylinder 28 and carriage 8 to the right from their FIG. 4 positions to their FIG. 5 positions. As a result, the carriage 8 shifts from line 64 to offset line 66. This changes the path of the sewing line but its ultimate path will also depend upon the shifting and stretching of the quilt due to the pull exerted on it. However, as the sewing operation comes to a completion, the carriage 8 will continue to pursue offset line 66 whereas, from experience, we know that the sewing line will now return to the starting point 25 along offset line 66. The machine will stop when carriage 8 reaches the point designated 67. At this point, the head-frame 4 will tilt causing bar 58 to engage and open bleed valve 56. This results in a return of the carriage from point 67 to starting point 25. Now the quilting machine may be unloaded, reloaded and otherwise readied for the next operation which will repeat the preceding one.

Having described my invention, I claim:

1. In a quilting machine of the type having a frame, a framemounted follower, a carriage, a carriage-mounted guide-track, a carriage-mounted quilt and a frame-mounted sewing machine wherein the follower drives the guide-track to move the quilt along a path reproducing an endless sewing line design while the sewing machine sews that design into the quilt and wherein said operation subjects the quilt to a horizontal pull which stretches and shifts the quilt relative to the carriage in a manner causing the end point of the sewn design go be offset in one direction from its starting point, an improvement comprising:

A. shift means interconnecting the guide-track and carriage,

said means being operative,

1. when actuated one way, to shift the carriage relative to the track in the contra offset direction from a normal position to a shifted position, and

2. when actuated the opposite way, to return the carriage relative to the track from its shifted position back to said normal position; and

B. control means operative,

1. during the sewing operation, to actuate the shift means said one way to shift the carriage, and

2. after the sewing operation, to actuate the shift means in said opposite way to return the carriage.

2. The improvement of claim 1 wherein A. said shift means comprises a double acting operating cylinder mounted on the carriage with its piston connected to the guide-track.

3. The improvement of claim 2 wherein:

A. the control means includes a double acting control valve operative,

1. when actuated one way, to actuate said operating cylinder said one way to shift the carriage, and

2. when actuated the other way, to actuate said operating cylinder said other way to return the carriage.

4. The improvement of claim 3 wherein:

A. the control means includes 1. a pair of first and second cooperative elements, the first being mounted on the carriage for movement therewith and the second being mounted on the frame in position to operate that first element during the sewing operation and thereby actuate the control valve one way for carriage shifting purposes.

5. The improvement of claim 3 wherein the frame of the machine conventionally includes a head-frame which is tilted following the completion of the sewing operation and wherein:

A. the control means includes 1. a pair of third and fourth cooperative elements, the third being mounted on the carriage for movement therewith and the fourth being mounted on the headframe in position to operate the third element when the head-frame is tilted and thereby actuate the control valve the other way for carriage return purposes.

6. The improvement of claim 1 wherein:

A. the control means includes a double acting control valve operative,

I. when actuated one way, to actuate the shift means said one way to shift the carriage, and

2. when actuated the other way, to actuate the shift means said other way to return the carriage.

7. The improvement of claim 6 wherein:

A. the control means includes 1. first valve actuating means mounted on the carriage for movement therewith and arranged in position to engage the frame during the sewing operation and through such engagement actuate the control valve one way for carriage shifting purposes.

8. The improvement of claim 6 wherein the frame of the machine conventionally includes a head-frame which is tilted following the completion of the sewing operation and wherein:

A. the control means includes 1. second valve actuating means mounted on the carriage for movement therewith and arranged in position to be engaged when the head-frame is tilted and, through such engagement, actuate the control valve the other way for cam'age return purposes.

9. The improvement of claim 8 wherein:

A. the control means includes 1. first valve actuating means mounted on the carriage for movement therewith and arranged in position to engage the frarne during the sewing operation and through such engagement actuate the control valve one way for carriage shifting purposes.

10. The improvement of claim 3 wherein:

A. said operating cylinder is an air cylinder which yieldably urges the carriage in the shift and return directions; and

7 8 B. said improvement includes stop means on the carriage to 8. means to tilt the head-frame following the end of the restrict said yieldable shift and return movements of the sewing operation;

B. shift means interconnecting the guide-track and carriage,

said means being operative, 1. when actuated one way, to shift the carriage relative to carriage relative to the guide-track. 11. An improved quilting machine comprising: A. a quilting machine of the type having l. a frame including a tiltable cross head-frame,

2. a sewing machine including a sewing head on the headframe,

3. a movable carriage means underlying the sewing head,

the track in the contra ofi'set direction from a normal position to a shifted position, and

2. when actuated the opposite way, to return the carriage relative to the track from its shifted position back to a normal position; and c. control means operative, in response to relative movement between the carriage means and the frame, 1. during the sewing operation, to actuate the shift means said one way to shift the carriage, and 2. after the sewing operation, to actuate the shift means in said opposite way to return the carriage 12. The machine of claim 1 1 wherein: A. said shift means comprises a double acting operating air cylinder mounted on the carriage with its piston connected to the guide-track,

1. said cylinder being operative to urge the carriage yieldably in the shift and return directions; and B. stop means on the carriage to restrict said yieldable shift and return movements of the carriage relative to the guide-track.

4. a carriage-mounted track providing the machine with 10 the pattern of a given endless sewing line design,

5. motorized means operative, when energized, to drive the sewing head and contemporaneously drive the track to move the carriage means from a given starting point along a path reproducing the pattern of said 15 endless sewing line design while the sewing mechanism sews that design into a carriage-mounted quilt, these motorized operations subjecting the quilt to a horizontal pull which stretches and shifts the quilt relative to the carriage means in a manner causing the end point of the sewn design to be offset in one direction from its starting point,

6. start means to energize the motorized drive means at the beginning of a sewing operation,

7. stop means to de-energize the motorized drive means at the end of a sewing operation, and 

1. In a quilting machine of the type having a frame, a framemounted follower, a carriage, a carriage-mounted guide-track, a carriage-mounted quilt and a frame-mounted sewing machine wherein the follower drives the guide-track to move the quilt along a path reproducing an endless sewing line design while the sewing machine sews that design into the quilt and wherein said operation subjects the quilt to a horizontal pull which stretches and shifts the quilt relative to the carriage in a manner causing the end point of the sewn design go be offset in one direction from its starting point, an improvement comprising: A. shift means interconnecting the guide-track and carriage, said means being operative,
 1. when actuated one way, to shift the carriage relative to the track in the contra offset direction from a normal position to a shifted position, and
 2. when actuated the opposite way, to return the carriage relative to the track from its shifted position back to said normal position; and B. control means operative,
 1. during the sewing operation, to actuate the shift means said one way to shift the carriage, and
 2. after the sewing operation, to actuate the shift means in said opposite way to return the carriage.
 2. when actuated the other way, to actuate the shift means said other way to return the carriage.
 2. when actuated the opposite way, to return the carriage relative to the track from its shifted position back to said normal position; and B. control means operative,
 2. after the sewing operation, to actuate the shift means in said opposite way to return the carriage.
 2. The improvement of claim 1 wherein A. said shift means comprises a double acting operating cylinder mounted on the carriage with its piston connected to the guide-track.
 2. when actuated the other way, to actuate said operating cylinder said other way to return the carriage.
 2. when actuated the opposite way, to return the carriage relative to the track from its shifted position back to a normal position; and c. control means operative, in response to relative movement between the carriage means and the frame,
 2. after the sewing operation, to actuate the shift means in said opposite way to return the carriage
 2. a sewing machine including a sewing head on the head-frame,
 3. a movable carriage means underlying the sewing head,
 3. The improvement of claim 2 wherein: A. the control means includes a double acting control valve operative,
 4. The improvement of claim 3 wherein: A. the control means includes
 4. a carriage-mounted track providing the machine with the pattern of a given endless sewing line design,
 5. The improvement of claim 3 wherein the frame of the machine conventionally includes a head-frame which is tilted following the completion of the sewing operation and wherein: A. the control means includes
 5. motorized means operative, when energized, to drive the sewing head and contemporaneously drive the track to move the carriage means from a given starting point along a path reproducing the pattern of said endless sewing line design while the sewing mechanism sews that design into a carriage-mounted quilt, these motorized operations subjecting the quilt to a horizontal pull which stretches and shifts the quilt relative to the carriage means in a manner causing the end point of the sewn design to be offset in one direction from its starting point,
 6. start means to energize the motorized drive means at the beginning of a sewing operation,
 6. The improvement of claim 1 wherein: A. the control means includes a double acting control valve operative,
 7. stop means to de-energize the motorized drive means at the end of a sewing operation, and
 7. The improvement Of claim 6 wherein: A. the control means includes
 8. The improvement of claim 6 wherein the frame of the machine conventionally includes a head-frame which is tilted following the completion of the sewing operation and wherein: A. the control means includes
 8. means to tilt the head-frame following the end of the sewing operation; B. shift means interconnecting the guide-track and carriage, said means being operative,
 9. The improvement of claim 8 wherein: A. the control means includes
 10. The improvement of claim 3 wherein: A. said operating cylinder is an air cylinder which yieldably urges the carriage in the shift and return directions; and B. said improvement includes stop means on the carriage to restrict said yieldable shift and return movements of the carriage relative to the guide-track.
 11. An improved quilting machine comprising: A. a quilting machine of the type having
 12. The machine of claim 11 wherein: A. said shift means comprises a double acting operating air cylinder mounted on the carriage with its piston connected to the guide-track, 